Resonance and mode locking in gaseous detonation propagation in a periodically nonuniform medium

In this work, we analyze numerically the dynamics of one-dimensional gaseous detonations propagating in a mixture with periodically varying properties such as density, temperature, or mixture composition. It is found that periodic upstream variations can lead to resonant amplification of intrinsic oscillations and to mode locking whereby the detonation oscillations are controlled more by the imposed mixture nonuniformities than by the detonation intrinsic instability. The results are consistent with predictions made in the recent work (Kasimov and Gonchar, Proceedings of 27th ICDERS, 2019; Proc Combust Inst 38(3):3725-3732, 2021) that analyzed the same problem in the framework of reactive Burgers' equation.